core-it-suite/src/test/resources/mng-7160-extensionclassloader/project-core-self-first/.mvn/extensions.xml

<extensions>
    <extension>
        <groupId>org.apache.maven.its.mng7160</groupId>
        <artifactId>extension</artifactId>
        <version>1.0</version>
        <classloadingStrategy>self-first</classloadingStrategy>
    </extension>
</extensions>